There has been a need for summarizing and establishing adequate aerodynamic and thermodynamic design criteria for turbojet engine test cells and ground run-up suppressors. These criteria are discussed and their uses are illustrated by examples of typical design problem solutions. The presence of noise suppression structures can have significant influences upon the operation of the turbojet engine. These influences are enumerated and evaluated with recommendations for establishing maximum acceptable effects. Typical test cell configurations are presented and design criteria are established for providing noise suppression facilities which may be utilized for testing a full size aircraft or an engine by itself. These facilities can be either permanent structures or portable units.